The present invention relates to driers of wet granular material such as, for example, pre-drained coal leaving washing tanks.
Centrifugal driers have a rotatable drum in which an entry part is fixed to form the continuation of a fixed supply duct. The entry parts rotates at high speed together with the drying drum and is arranged to receive material to be dried from the supply duct and to direct this material towards the peripheral drying wall of the drum.
Hitherto, the entry part has generally consisted of a cone section fixed to the base of the drum by several supports. This cone section receives the material to be dried through its narrowest circular opening and directs it towards the drum drying wall through its widest circular opening.
Such a conventional cone section has several drawbacks:
(a) The material to be dried slides over its inner surface with a small degree of friction such that its circular accelerating effect vis-a-vis the material is small. This means that the material is unevenly distributed and "pockets" are formed within the drum, causing undesirable vibration of the drum and inefficient drying of the material.
(b) The material is introduced into the entry part at high speed and therefore causes rapid wear to the entry part which must therefore be frequently replaced.
(c) The supports of the cone section are prone to rapid wear.
(d) The material enters the drying drum at too low a circular speed compared to the speed of this drum. This results in rapid wear of the drum at its impact zone.
It is an object of the invention to reduce the above described drawbacks.